Error with current BuiltInDS + GWT 2.7.0 + normal DevMode

[Blama]

Hi Isomorphic,

I get the following error in Eclipse's Development Mode tab when I start a untouched BuiltInDS (v10.0p_2015-05-19) in normal DevMode and hit the launch URL with Firefox.

23:07:06.614 [ERROR] [builtinds] Failed to load module 'builtinds' from user agent 'Mozilla/5.0 (Windows NT 6.3; WOW64; rv:26.0) Gecko/20100101 Firefox/26.0' at 127.0.0.1:49410

java.lang.IncompatibleClassChangeError: class com.google.gwt.dev.javac.asm.CollectMethodData has interface org.objectweb.asm.MethodVisitor as super class
    at java.lang.ClassLoader.defineClass1(Native Method)
    at java.lang.ClassLoader.defineClass(Unknown Source)
    at java.security.SecureClassLoader.defineClass(Unknown Source)
    at java.net.URLClassLoader.defineClass(Unknown Source)
    at java.net.URLClassLoader.access$100(Unknown Source)
    at java.net.URLClassLoader$1.run(Unknown Source)
    at java.net.URLClassLoader$1.run(Unknown Source)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.net.URLClassLoader.findClass(Unknown Source)
    at java.lang.ClassLoader.loadClass(Unknown Source)
    at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
    at java.lang.ClassLoader.loadClass(Unknown Source)
    at java.lang.Class.getDeclaredMethods0(Native Method)
    at java.lang.Class.privateGetDeclaredMethods(Unknown Source)
    at java.lang.Class.getDeclaredMethod(Unknown Source)
    at java.io.ObjectStreamClass.getPrivateMethod(Unknown Source)
    at java.io.ObjectStreamClass.access$1700(Unknown Source)
    at java.io.ObjectStreamClass$2.run(Unknown Source)
    at java.io.ObjectStreamClass$2.run(Unknown Source)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.io.ObjectStreamClass.<init>(Unknown Source)
    at java.io.ObjectStreamClass.lookup(Unknown Source)
    at java.io.ObjectStreamClass.initNonProxy(Unknown Source)
    at java.io.ObjectInputStream.readNonProxyDesc(Unknown Source)
    at java.io.ObjectInputStream.readClassDesc(Unknown Source)
    at java.io.ObjectInputStream.readOrdinaryObject(Unknown Source)
    at java.io.ObjectInputStream.readObject0(Unknown Source)
    at java.io.ObjectInputStream.defaultReadFields(Unknown Source)
    at java.io.ObjectInputStream.defaultReadObject(Unknown Source)
    at com.google.gwt.dev.javac.CachedCompilationUnit.readObject(CachedCompilationUnit.java:204)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at java.io.ObjectStreamClass.invokeReadObject(Unknown Source)
    at java.io.ObjectInputStream.readSerialData(Unknown Source)
    at java.io.ObjectInputStream.readOrdinaryObject(Unknown Source)
    at java.io.ObjectInputStream.readObject0(Unknown Source)
    at java.io.ObjectInputStream.readObject(Unknown Source)
    at com.google.gwt.dev.javac.PersistentUnitCache.loadUnitMap(PersistentUnitCache.java:574)
    at com.google.gwt.dev.javac.PersistentUnitCache.access$800(PersistentUnitCache.java:103)
    at com.google.gwt.dev.javac.PersistentUnitCache$4.run(PersistentUnitCache.java:232)
    at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source)
    at java.util.concurrent.FutureTask.run(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
    at java.lang.Thread.run(Unknown Source

My setup is current google Plugin for Eclipse + GWT 2.7.0 (manually installed), Eclipse Luna SR2, Win 8.1, FF26 with google GWT Developer Plugin.

According to a fast search for "java.lang.IncompatibleClassChangeError: class com.google.gwt.dev.javac.asm.CollectMethodData has interface org.objectweb.asm.MethodVisitor as super class" this is due to GWT 2.7.0 requiring a new asm.jar. You include asm-3.1.jar.
Replacing the jar with the newer version (asm-5.0.4.jar (and unchanged asm-attrs.jar)) in the build path lets me start the normal Development Mode without problems.

Can you reproduce this? As long as SuperDevMode is not the perfect (or only) debugging solution this might be very annoying for new users.

The JavaModuleDependencies docs also do not mention asm.jar as dependency. Is it a general GWT dependency? Because in my project I just don't have it. Most likely I removed it because it is not listed somewhere.

Best regards
Blama

[Blama]

Hi Isomorphic,

this gets strange. Now I got a similar exception also for SuperDevMode, which I'm very sure worked before.

Also here: As I'm not really stopped by this and there is a workaround (not using the lib or upgrading it), it has no priority for me.

Best regards
Blama

[Blama]

Hi Isomorphic,

can you confirm this change is necessary and OK to do? I need to build a testcase and in order to do so I'll introduce this change to the BuiltInDS buildpath.

Best regards
Blama

[Isomorphic]

We don't use asm-3.1.jar directly, we include it because it's a dependency for hibernate-core.

We're not aware of which specific Hibernate features depend on it (removing it didn't break some simple tests) or whether Hibernate can use the newer library.

Note also that technically, GWT only needs "asm" at compile time and Hibernate only needs "asm" at runtime - separate classpaths for these two stages could resolve a dependency clash if there is one.

[Blama]

Hi Isomorphic,

OK, thank you. Perhaps you should upgrade it then in the samples because otherwise many people will run into this.

Best regards
Blama

[Blama]

Hi Isomorphic,

can you please upgrade this? I can't start the BuiltInDS sample from the current 5.1d nightly in Development Mode without replacing the file with the newer version.

Can you reproduce this? Please try to hit the DevMode-URL from FF26 (Win8.1) and see the error in the Eclipse Development Mode log.

This is really annoying as this is an always required prerequisite step in order to produce a testcase for a new nightly.

Best regards
Blama

[Isomorphic]

We tried with SGWT 5.1d Eval 2015-07-27, Eclipse Luna (4.4.2), Windows 8.1 x64, and FF 26, and we were able to run Dev Mode on BuiltInDS flawlessly, modify the Java, set breakpoints, etc. No problems were observed.

BTW, FF24 ESR is the preferred FF version for Dev Mode, since it was maintained until 10/14/2014, whereas FF26 end-of-life was 2/4/2014.

[Blama]

Hi Isomorphic,

I just noticed that you now ship asm-3.1.jar AND asm-5.0.4.jar in your 6.1p zip-file. Only SGWTPOWER_HOME/lib/asm-5.0.4.jar is linked in .classpath of BuiltInDS.

Best regards
Blama